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/*++
/* NAME
/* make_dirs 3
/* SUMMARY
/* create directory hierarchy
/* SYNOPSIS
/* #include <make_dirs.h>
/*
/* int make_dirs(path, perms)
/* const char *path;
/* int perms;
/* DESCRIPTION
/* make_dirs() creates the directory specified in \fIpath\fR, and
/* creates any missing intermediate directories as well. Directories
/* are created with the permissions specified in \fIperms\fR, as
/* modified by the process umask.
/* DIAGNOSTICS:
/* Fatal: out of memory. make_dirs() returns 0 in case of success.
/* In case of problems. make_dirs() returns -1 and \fIerrno\fR
/* reflects the nature of the problem.
/* SEE ALSO
/* mkdir(2)
/* LICENSE
/* .ad
/* .fi
/* The Secure Mailer license must be distributed with this software.
/* AUTHOR(S)
/* Wietse Venema
/* IBM T.J. Watson Research
/* P.O. Box 704
/* Yorktown Heights, NY 10598, USA
/*--*/
/* System library. */
#include <sys_defs.h>
#include <sys/stat.h>
#include <errno.h>
#include <string.h>
#include <unistd.h>
/* Utility library. */
#include "msg.h"
#include "mymalloc.h"
#include "stringops.h"
#include "make_dirs.h"
#include "warn_stat.h"
/* make_dirs - create directory hierarchy */
int make_dirs(const char *path, int perms)
{
const char *myname = "make_dirs";
char *saved_path;
unsigned char *cp;
int saved_ch;
struct stat st;
int ret;
mode_t saved_mode = 0;
gid_t egid = -1;
/*
* Initialize. Make a copy of the path that we can safely clobber.
*/
cp = (unsigned char *) (saved_path = mystrdup(path));
/*
* I didn't like the 4.4BSD "mkdir -p" implementation, but coming up with
* my own took a day, spread out over several days.
*/
#define SKIP_WHILE(cond, ptr) { while(*ptr && (cond)) ptr++; }
SKIP_WHILE(*cp == '/', cp);
for (;;) {
SKIP_WHILE(*cp != '/', cp);
if ((saved_ch = *cp) != 0)
*cp = 0;
if ((ret = stat(saved_path, &st)) >= 0) {
if (!S_ISDIR(st.st_mode)) {
errno = ENOTDIR;
ret = -1;
break;
}
saved_mode = st.st_mode;
} else {
if (errno != ENOENT)
break;
/*
* mkdir(foo) fails with EEXIST if foo is a symlink.
*/
#if 0
/*
* Create a new directory. Unfortunately, mkdir(2) has no
* equivalent of open(2)'s O_CREAT|O_EXCL safety net, so we must
* require that the parent directory is not world writable.
* Detecting a lost race condition after the fact is not
* sufficient, as an attacker could repeat the attack and add one
* directory level at a time.
*/
if (saved_mode & S_IWOTH) {
msg_warn("refusing to mkdir %s: parent directory is writable by everyone",
saved_path);
errno = EPERM;
ret = -1;
break;
}
#endif
if ((ret = mkdir(saved_path, perms)) < 0) {
if (errno != EEXIST)
break;
/* Race condition? */
if ((ret = stat(saved_path, &st)) < 0)
break;
if (!S_ISDIR(st.st_mode)) {
errno = ENOTDIR;
ret = -1;
break;
}
}
/*
* Fix directory ownership when mkdir() ignores the effective
* GID. Don't change the effective UID for doing this.
*/
if ((ret = stat(saved_path, &st)) < 0) {
msg_warn("%s: stat %s: %m", myname, saved_path);
break;
}
if (egid == -1)
egid = getegid();
if (st.st_gid != egid && (ret = chown(saved_path, -1, egid)) < 0) {
msg_warn("%s: chgrp %s: %m", myname, saved_path);
break;
}
}
if (saved_ch != 0)
*cp = saved_ch;
SKIP_WHILE(*cp == '/', cp);
if (*cp == 0)
break;
}
/*
* Cleanup.
*/
myfree(saved_path);
return (ret);
}
#ifdef TEST
/*
* Test program. Usage: make_dirs path...
*/
#include <stdlib.h>
#include <msg_vstream.h>
int main(int argc, char **argv)
{
msg_vstream_init(argv[0], VSTREAM_ERR);
if (argc < 2)
msg_fatal("usage: %s path...", argv[0]);
while (--argc > 0 && *++argv != 0)
if (make_dirs(*argv, 0755))
msg_fatal("%s: %m", *argv);
exit(0);
}
#endif
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